The Baltimore Longitudinal Study of Aging (BLSA) is an ongoing, multidisciplinary research project aimed at understanding the aging process in men and women. Longitudinal changes are assessed by having a cohort of community-dwelling subjects of both sexes, and ages across the adult lifespan, who return every two years for a comprehensive evaluation. Major goals of the study are to better understand age-related changes in various organ systems and their interrelationships, to characterize the transition from normal to pathological aging, and to relate functional changes in these systems to the development of specific diseases and mortality. The purposes of the BLSA are fourfold: 1) to obtain repeated measures of physiological, pathological, biochemical, and psychological variables on longitudinal study participants; 2) to compare levels of function repeatedly measured in age and sex cohorts; 3) to follow changes in individual participants and groups of participants up to and beyond age-related endpoints and disease events; and 4) to identify characteristics of individual participants that may be markers of biological aging, and to analyze their influence on clinical outcomes. Cross-sectional characterization of multiple parameters is also obtained and differences related to age, sex and race are quantified. Aging, secular, and period effects are examined. Relationships between such variables as nutritional habits, customary levels of physical activity, and adaptations to age-associated physical disability with glucose metabolism, cardiovascular function and specific disease outcome are being examined. Studies of some BLSA participants are conducted on Johns Hopkins Bayview Medical Center's GCRC and include assessments of nutritional patterns and oral glucose tolerance testing. Over the past year, major reports have been published in relation to diabetes and glucose metabolism, osteoarthritis, Alzheimer's Disease, cardiovascular disease, prostate cancer, and women's health. The BLSA is part of the Intramural Research Program of the National Institute of Aging and wholy supported by the NIA. The GCRC staff intereviewed 379 of the BLSA participants for nutritional assessment. Twenth-five of approximately 500 subjects seen during the reporting period were admitted to the GCRC for testing. The enrollment period for this study is ongoing.